甜瓜种皮颜色控制基因CmSC1的精细定位及候选基因分析  

Fine Mapping and Candidate Gene Analysis of Seed Coat Color Gene CmSC1 in Melon

作　　者：马建[1] 李丛丛 黄亚婷 谢雨黎 程玲玲 王建设[1] MA Jian;LI CongCong;HUANG YaTing;XIE YuLi;CHENG LingLing;WANG JianShe(Beijing Vegetable research Center,Beijing Academy of Agriculture and Forestry Sciences/Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(North China),Ministry of Agriculture and Rural Affairs,Beijing 100097;Beijing Agro-Biotechnology Research Center,Beijing Academy of Agricultural and Forestry Sciences/Beijing Key Laboratory of Agricultural Genetic Resources and Biotechnology,Beijing 100097)

机构地区：[1]北京市农林科学院蔬菜研究中心/农业农村部华北地区园艺作物生物学与种质创制重点实验室,北京100097 [2]北京市农林科学院北京农业生物技术研究中心/农业基因资源与生物技术北京市重点实验室,北京100097

出　　处：《中国农业科学》2021年第10期2167-2178,共12页Scientia Agricultura Sinica

基　　金：国家自然科学基金(31701937);蔬菜中心科研创新基金(KYCX202001-11);北京市农林科学院科技创新能力建设专项(KJCX20200113)。

摘　　要：【目的】通过对甜瓜种皮颜色进行遗传分析及基因精细定位,并推测其候选基因和开发特异分子标记,为下一步该基因的功能研究及合理利用奠定基础。【方法】利用白色种皮材料HP22和黄色种皮材料B8、B150分别配制杂交组合,获得后代遗传分离群体并进行种皮颜色的表型调查及遗传分析,通过基因图位克隆方法完成基因的精细定位。通过对定位区间内注释基因进行编码区序列和功能分析确定关键候选目的基因。【结果】甜瓜白色种皮对黄色种皮为显性,由单显性基因CmSC1控制并表现延迟遗传效应。利用368个黄色种皮F2单株最终将CmSC1精细定位于第5号染色体分子标记S27和S28之间物理距离约95 kb区间内,共包含12个注释基因。其中一个为拟南芥AtTT8同源的编码bHLH转录因子蛋白的MELO3C014406,经序列变异位点分析,黄色种皮材料B8和B150分别在该基因ATG下游第47位碱基处插入碱基A以及在第260位碱基处缺失14 bp导致翻译蛋白提前终止,致使后面功能结构域完全缺失,进而通过开发特异分子标记YS及序列分析,发现65份黄色种皮材料均发生这两种突变形式中的一种,推测MELO3C014406即为控制种皮颜色CmSC1的目的基因。【结论】本研究将控制种皮颜色的CmSC1精细定位于第5染色体95 kb区间内,推测MELO3C014406为最终目的基因,并开发了特异分子标记YS。【Objective】In this study,the genetic analysis and fine mapping of melon seed coat color gene were performed,and the candidate gene was isolated and the molecular marker developed,so as to provide a foundation for gene function and rational utilization.【Method】The inbred line HP22 with white seed coat was crossed with the inbred line B8 and B150 with yellow seed coat,and the offspring population was obtained,respectively.The seed coat colors of offspring plants were investigated by visual inspection.The locus of gene was fine mapped through map-based cloning strategy,and the candidate target gene in the mapping region was determined by gene sequencing and function analysis of gene coding region.【Result】The white seed coat was dominant to yellow,which was controlled by a single dominant gene locus,named CmSC1,showed delayed genetic characteristic.Using 368 yellow seed coat individuals from F2 population,the target gene CmSC1 was delimited to a 95 kb interval flanked by markers S27 and S28 on chromosome 5 that contained twelve annotated open reading frames(ORFs).Among of them,the MELO3C014406 gene encoded a bHLH transcription factor protein which was homologous to the Arabidopsis AtTT8 gene.Sequence analysis of MELO3C014406 gene in the yellow seed coat inbred lines indicated that two types of sequence variation were identified.The first type was an A insertion at the 47th base pairs position downstream of ATG,and the other was a 14 bp deletion at the 260th base pair position downstream of ATG,which caused premature termination and produced truncated proteins,respectively.Furthermore,the sequencing analysis of 65 yellow seed coat accessions were detected by specific molecular marker YS,and the results showed that they all contained one mutation type of two variation types.These results suggested that the MELO3C014406 gene was an ideal candidate gene for CmSC1 controlling seed coat color.【Conclusion】In this study,the CmSC1 gene regulating seed coat color was finally mapped to a 95 kb interval,and the M

关 键 词：甜瓜 种皮颜色 基因定位 原花青素 bHLH转录因子 

分 类 号：S652[农业科学—果树学]